Paddle-shaft mounting for etching machines



' Nov. 24, 1925- A. HOLMSTRM PDDLE SHAFT MOUNTING FOR ETCHING MACHINES Filed Aug. 20, 1923 5v Sheets-Sheet 2 llm/ Nov; 24, 1925- 1,562,642

A. HOLMSTRM PADDLE SHAFT MOUNTING FOR ETCHING MACHINES Filed 'Aug'. 20, 1923 5 Sheets-Sheet 5 lll Patented Nov. 24, 1925.

UNITED STATES PATENT OFFICE- uur. HoLMsrE/n, oEvILLA- AEEovrx, vIooEYHoLM, SWEDEN.

:ennnLE-SHAIl-,r 'MOUNTINGTOR Eremita macnrnns.

Application med August 20, 1923. Serial No. 658,478.

To aZZw/wm it may concern:

Be it known that l, AXEL HoLMsrRM, av subject of the ling of Sweden, residing at lfilla Aerovik, Viggbyholm, Sweden, have invented a certain new and useful Paddle- Shait Mounting for Etching Machines, of which the following is a specication.

ll/ly invention relates to etching machines andmore partieularlyv to etching machines in which the acid is sprayed upon the plates to he etched hy means oit a revolving paddle., and to the mounting ot the paddles.

The main purpose olf my invention is to provide inexpensive means lor easy inser tion and the replacement ofthe paddle, as well as tor easy adjustment in the relative positions ci the paddle sections.

l Jfurther purpose is to prevent 'the sprayed liquor trom getting without the loon at the shalt opening, shaping sleeves extending through the openings so as to utilize centrifugal torce upon any liquor falling upon the Isleeves to return the liquor to the con.

t. A further purpose is to radially llare the sleeves as they entend inwardly in order to make liquor falling upon them travely inwardly.

A further purpose is to radially ilangethe sleeves at their inner ends so as to make liquor reaching their outer ends dow radially outward, i

Further purposes will appear in the specication and in "the claims. .f Y l have preferred toillustrate my inven- 'tion hy a ltew forms only oit' the many in which it may appear, selecting these hecause they well illustrate the principles involved, while at the same time they are inexpensive and ecient; y

Figure l. is a sectional diagrammatical view'to :illustrate the position and duty of apaddle used in etching.

Figure 2 is a side elevation ,of an etching'l hon equipped with my invention.

Figure 3 is a broken lsection vupon the line S-B'ol Figure 2.

vFigure l is broken enlarged detail from Figure 3.

Figures 5 and 6 show in loroken section' grammatically in Figure l..

Figures 7 to ll are broken sectional Velevations indicating modifications ofdetails.

ln all drawings liltevnumbers refer to like parts.

Referring to the drawings and describing in illustration and not in limitation In etching devices ot' this character the acid is conveniently placed within a stonei at each end.;

` The etching process is well illustrated dia- 'llhe level 0l the etching liquor is well helow the shalt. il revolving blade upon the paddle dips into the liquor, piclrs up the liquor and casts it against in sucha way as to spray it upon the plates placed along an opposite wall oi the loon.

The stoneware tanlr ll is hjlled withJ etching liquor to a level a-a considerably helow the shaft l5. which carries the stoneware paddle ltt. The shalt -l'eirtends through the sides o'l the hon to suitable hearings 17, as seen in Figures 2 and S'. The revolving paddles cast the etching liquor into the hatde space 18 and-past the loae l9 against plates 20 set upon a groove 2l 'along the stoneware rest plate 22. Thabor has a re dll .clear through the hou and having a hearing movable cover 23 and a glass cover ortion 2l usually lett in place.. A tan 25 raws av continuous 4.stream ot air into the loon through an opening 26" and spaces 27 and 28 at the ends of the shalt and carries ed' the fumes with the air to a suitable chimney not shown'. l

When etching 'a plate removed, if it he on, the plate 20 is set the cover is krstA upon the groove 2l, the cover 23 is replaced,l

the paddle is started and kept running for a suitable time drenching` the plate with etching liquor; the paddle is then stopped,l

the cover removed andthe platetaken out and washed tree trom ,etchingliquor A ico dropping a plate upon a paddle section, a

short section only will haveto be re laced. This arran ement too permits staggering the blades ofit e different sections thereby giv- 'ino more uniform torque and spray.

itherto it has been usual to assemble the paddle sections loosely upon the shaft through the top of th box and then while in the box to seal them to the shaft by flowing between the haft and the paddle hubs a molten compou d, such as pitch,- which I `and skill to do this properly and frequently hardens on coolin and maintains ythe paddle sections rigid wit the shaft.

When a paddle section has broken it has been necessary to cai'efullv heat the paddle sections while in the box to melt the compound sealingthem to the shaft so as to be able to slide out the sections to the broken one by sliding out the shaft; a new section and the unbroken old sections to be put back in the same way. It has requird'both time unbroken sections have broken in heating, burst by the swelling compoundA or cracked by unequal expansion.

My invention is directed .toward simultaneously lessening the cost and time and `skill needed for the replacement of broken sections, and also in providing an arrangement whereby the centering of the paddle sections with respect yto the shaft becomes automatic and an lar adjustment in the positions of the b ades `very easy, while at the same time the side openings and the shaft are effectively sealed from the etching li uor and from the fumes thereof.

qlhe bearings 17 are supported b brackets 36 upon the cross bars 37-clampe to place against rubber washers 38` upon the outside of the box by. tie ro'ds 39.

The central'portion of the shaft isfpreferably provided with protective enamel 40 which may be of asphaltum orrother acidresistant paint. Y f

The soft resilient sleeves 41 between the shaft and the hubs 42 are `provided with 'radial flanges 43 across the Vends :of the hubs to form resilient gaskets betweenthe paddle sections.I The sleeves 44, at thes'ides of the box,- are of stoneware orother acid-resistant material. They extend through the box'and .are pressed inward, between washers and '46 and nuts 47 y and 48 threaded-upon the shaft. Their ner faces pressiagainst the `may get to these washers is usu antimafia gaskets 43 of the ad'acent paddle sections, thereb sealing the s aft from acid of the box. hese sleeves are so shaped that centrifugal force guides the spray fallingupon I them toward the interior of the box.

The washers 45 and 4 6 are r ciently soft to seal the shall at the outer end of the sleeves against any seepa e of etching liquor from along the outsi e of the sleeves, and to provide easy connection eferably sufbetween the sleeve and nut. I have found aluminum a suitable materialv for these washers and that the quantity of liqluor that a ly very small. Where these washers are harder than aluminum -or where conditions are such, that there is likelihood of more than a minute quantity of liquor reaching them additional gasket washers of acid-resistant `material may be inserted between the-washers and the sleeves, as in Fi re 7.

The sleeves at t e sides of the box are preferably tapered, flaring as they extend in ward so that any liquor reaching the sleeve wnl tend to flow inward by reason of centrifugal force. The openings through the box walls for the sleeves taper to correspond to the taper of the sleeves. Drain grooves 49 and 50, respectively upon the exterior of the sleeve and the interior of the opening in the box wall are provided to catch liquoi` that Lmay tend to run along the sleeve after the paddle has stopped revolving, and the groove or grooves 49 lof the sleeve are placed further in along the shaft than the grooves 50 so that any liquor `cast from these grooves when the paddle starts that ay strike the toprof the openin through thhlbox and tend to `run outward y will be caught in the groove 50.

In Figures 3, 4 and 8 the box walls are Aprovided with animvard boss 51 around each tapered opening and this boss is radially flanged at 52 around its inner end so' that any liquor falling upon the boss will ilow around the outside of the boss to fall oil at the bottom without an opportunity to et into the opening.

n Figure 8 the ta er of the sleeve extendsto the inner end of t e sleeve and during rocentrifugally to the paddle and thence out ,centrifugally to be sprayed from the blades,

and when the paddle stops, substantially all that mayl tend to flow outwardly along the top of t e sleeve or'the top ofthe opening will be caught in one or other of the grooves and returned to the box. The bottom of the boss is-slotted at 53 for thereturn to the box of any liquor reaching the bottom of the openin l In Figures 3 and 4 the sleeve at its inner` end is radially flan ed'at and inclined diagonally backwar -and outward at 55 to lll tol

. easy to put on or cti.

cover the clearance space 56 between the inner edge of the boss and the tiange 54, preferably extending beyond the raised rim 52 of the boss. The end of this diagonal flange 55 is covered by the conical Hangs portion 57 of the loon, ccnicallyvinclined toward the shaft. The conical :tiange 57 performs the double function /of shielding the flange 55 from any hard object accidentally dropped from above and of shielding/the space 58 around the boss 5l from anyviolent slushes of etching liquor Whenstarting or stopping the paddle. The ange 57 isjlett open at the bottoni at 59 lfor drainage bach to the box;

lt is obvious that the diderent elements of the arrangement tor preventing the liquor from getting out the opening "for the shaft have independent value as Well as their value inthe combinations shovvn and claimed and they maybe variedconsiderably Without departing :troni the invention. Thisis Well izllustrated by thei forms shown in Figures to ll.

lin Figure 7 the inward boss 5l and the sleeve it are made straight insteadlot` taper and theonter hood 57' and groovesfdtl and 50 oi Figure l are dispensed `yvitlin in Figure 9K/the reversely inclined dange terminal (55 oit Fi ures el and 7) oi the sleeve is dispensed with, thegrcoves however being shovvn.

ln Figures lOand ll the bess around the sleeve is outside instead ci inside the bei; in Figure l0 the bor; is recessed or dished around the radial flange ci the sleeve, a lip 5'? (analogous to the hood 57 ci Figure d) protecting the flange trein' slushes or liquor .and trom objects above. lin Fignreli the Y. radial flange is left uncovered. The. soit resilient flanged sleeves il', dil,

are preferably el Alll-sections as seen in Fignres 3, et and -ll.. @ne oi' these sections is inserted in each end of each paddle section, making paddle section units having ends, faced by the lianges d3 and hushed by the sleeves al titting the shaft. ln this arrangement the bushing-dange sectionsv and the sections for the paddles are all alike and interchangeable. ln Figznres 5 and 6 are shown modiiied forms ci' these) bushingiiange sections.l ln'Figure 5 it is made of a' section, te` simultaneously fit vtwoy of lthe paddle sections. 'lghis torni however is considered less desirable than the interchangeable form ot Figure 4, and With it the individual paddle sections are somewhat less ',lhe :torni oi Figure 6 `is like that oi Fig- `ure 4 except that the sle-eveis yconical instead .of cylindrical? to iita corresponding conical bore of the paddle section.

"When replacing a section one of the vnuts "All" or 48 is taken ,oii' and the shaft is slid out longitudinally, with or Without lirst starting the rubber sleeves tol slide on the shat by slightly tightening the other nut; the paddle section units are lifted out from the top of the box one at a time until the rbroken unit has been taken out. The new unit .and unbroken old unit-sare then put back in the same Way, from the top oi the box, and finally are clamped between the nuts. i

lt will be `obvious too that the openings for the shaft in opposite sides of the borare so sealed as to prevent either the etching liquor or its fumes escaping at these holes.4

And further it will be obvious, that the `shaft is Well protected and sealed from the'y by Letters Patent is l invention,

ae desire te secure l. ln a paddle `Wheel assemblage for an Y etching machine, the combination ci a t,

rality ci' paddle secticns, a driving ough sections,

elli

adapted te pasa a sleeve i eno. oit the driving shf t,

roving tnesleeves atively other cushirncf1 te reel sections axially 'l ff." 1 v /I e sections-and elle t it ra ily tor snpperting and sealing the sections and ter vibration in thesecticns ln etching nia-chine, a internally resistant to etchi openingfa norman,x passing through opening, a paddle resistant to etching liquorpand having heb ot' larger bore than and` surrounding the shalt, and" a soit rub# berO sleeve connection between the shaft and hub.

3; ln an p tion unitihaving a hubfbuslned land fifa/,ced

with rubber, a lshalt apen which` the` heb is removably Aand,resiliently'inonnted and 4 rneansfsinrronndingA the shaft Aand A'resistant to etchingxliquor lremovably clampingv'tbe iaces'et' the hub..

f ln an etching'inaehine, al :pia-dlelle sec er and having an fr etching machine, a paddle section',l having a hub, alianged bashing otresilient n1alterial bushing and a'cing e'achff end of the buba shaft through the hub and connected thereto by the bushings and,inesattav4` surrounding the shait and resistant te @pc y ing liquor removably clamping th@ faces, of `thee-ut,l

`5. in ari-etching machine; a paddle :speci-"A tion havinga hub, a flanged. bushing ol rel lsiflient and acid-resistant materialV bushing and ..tacing'each Vend` et thdbub, a shalt `bushing of resilient material remova bushing and facing each end of the hub,.

through the hub and connected thereto by the bushings and means surrounding the shaft and resistant to etching liquor removably clamping the faces of the hub.

6. In an etchingl machine, a paddle section having a hub, an L-se'ction Hangd Y a shaft through the hub and connected thereto by the bushings, and means surrounding the shaft and resistant to etching qigor removably clamping the faces of the 7'. Iii anI etching machine, a box internally resistant'y to etching liquor and having an opening, a ,shaft normally passing through the opening, a pair of paddle sections resistant to etching liquor and having hubs of `larger bore than the shaft, removable means for connectingnd relatively centering the paddle sections andd the shaft, a `gasket between the'hubs and surrounding the shaft, andn other removable means surrounding. the

shaft and clamping the hubs together against 5 the gasket.

8. In an etching machine, a box internally resistant to'etching liquor and having opposite lateral openings, a shaft passing through the openings, threads upon the shaft, a plurality of resilient paddle section supports upon the shaft, paddle sections upon the supports, spaced thereby from the shaft and from each other and clamping means including nuts`mounted upcon the shaft threads for holding the shaft sections together axially of the' shaft.

nally resistant to etching liquor and having opposite lateral openings`, a shaft normally passing through both openings, a plurality of liquor resistant paddle sections within the boxresiliently and removably mounted along the shaft, gaskets therebetween, a liquor-resistant sleeve atand through each opening upon the shaft, a gasket between each sleeve and its adjacent paddle section, and nuts threaded upon thershaft, one at the .outer end of each sleeve adapted together to adjustably inwardly position and to clamp the different sections-into the gas.

kets.

n 10. In-an etching machine, a box internally resistant to etching liquor and having a lateral opening, a shaft normally passing through the opening, `a paddle section resistantto etching liquor within the box' and mounted upon the-shaft and a liquor-resistant sleeve mounted upon the shaft through the opening to seal again/st the paddle section and'tapering so as to radially` Hare as it extends inwardly. A

11. In an etching machine, arbox internally resistant to etching liquor and having alateral opening which slopes-downwardly and inwardly at the bottoml so as to drain into the box interior, a shaft normally passing through the opening, a paddle section mounted upon the shaft throug the opening, the larger end being inward and having at its inner enda. radial flange sealing with the paddle section.

12. In .an etching machine, a box inter-J nally resistant to etching liquor havingalateral opening drainin into the` box interior and a circumferentia groove about the interior of the opening' communicating with the drain, a shaft normally passing 'through the opening, a paddle section resistant to etching liquor within the box and mounted upon the shaft, and a liquor-resistant removable sleeve mounted upon the shaft through the opening, sealing with the paddle section and having within the opening an external circumferential groove for drainage.

13. In an etching machine, a box internally resistant to etching liquor havingalateral opening draining' into the box and aA circumferential groove about the interior of the opening communicating with the drain, a shaft normally passing through the opening, va paddle section resistant to etching liquor within the box and mounted upon the shaft, and a liquor-resistant removable sleeve mounted upon the shaft through the opening, sealing with the paddle section and having inwardly from the groove rof the 100 opening but within the opening an external 9. In an etching machine, a box inter? circumferential groove for drainage.

14. I n an etching machine, a box internally resistant to etching liquor having a lateral opening, an inwardly extending` boss "5 on the box around the opening radially Hanging at its inner end to form a drainage groove "around the outside of `the boss, a shaft normally passing through the o ening,

a paddle section resistant to etching liquor- H0 within the box and mounted on the shaft, and a `liquor-resistant `removable sleeve mounted upon the shaft through the open'- ing, radially Hanging at its inner end in sealing with the paddle sectionand thence .H5

diagonally Hanging backward and outward to .hoodthe inner edge of the boss.A

15. In an etching machine, a box internally -resistant to etching liquor having a lateral o ening, aninwardly extending boss "3 ing, apaddle section resistant to etchingl25 -liquor within the box and mounted on the. shaft, a liquor-resistant removable sleeve mounted upon the shaft-through-.the opening, radial y Hanging at its inner end in sealing with th'epaddle section and thence 13 diagonally Lilanging' backward and outward to hood the inner ed e of the boss, and an outer hood conically anging from the wall of the box toward the shaft around the outside ofthe backward flange of the sleeve and having a drain opening at its lower side.

16. In an etching machine,'a box internally resistant to etching liquor and having a lateral opening internally flaring inward and draining to the box, a paddle section resistant to etching liquor within .the box and mounted on the shaft, a liquor-resistant sleeve mounted upon the shaft through the opening, radially flaring as it extends inward and radially Hanging' at its -inner end in sealing against the paddle section,', and aninwardly extending boss on the wall of the box around the opening and radially 1 'tlanging at its inner end.

17. In an etching machine, al box internally resistant to etching liquor and having a lateral opening internall flaring inward and draining inward, an inwardly extending boss'around the opening on the box flanged outward` at its inner` end, a paddle section resistant 'to etching liquor mounted upon the shaft within the box, a liquor resistant sleeve mounted removably u on the shaft through the opening, radially arlng as it extends inward, rad'ally langing at its inner end insealing aganistthe paddl section and thence diagonally Hanging backwardly and outwardly to hood the in- .ner rim of the boss, and an outer hood` conically Hanging from the wall of thebox inwardly toward the shaft around the olitside of the backwardly extending flange of the sleeve and having' a drain opening at its lower side. y

' 18; In an etching machina a box iirternally resistant to etching liquor and having a lateral opening internally, ilaring and hooded at its inner end, a paddle section resistant -to etchin liquor mounted upon the shaft within the ox, and a liquorresistant sleeve 'radially ilariig within the hood and sealing with the pad e section.

@dan

l 19. In a paddle wheel unit, a paddle wheel shaft, a sleeve upon each end'of the shaft, a nut upon the'shaft at oneJendand a stop at the other adapted Ito clamp the sleeves relatively, and a plurality of interspersed paddle .wheel sections and gaskets 'maintained in sealing enga-gement axially of the shaft by pressure from thenut.

20. In an etching machine, a box internal- 'overhang the end of the sleeve.

21. In an etching machine, a box internally resistant to 'etching-liquor and having llateral openings, a stationary inwardly extending boss continuing one of the openings,

a paddle wheel within the box, a shaft for the Apaddle wheel extending through the openings, a sleeve surrounding the shaft and extending outwardly from the inside into one of the openings, lan inner flange upon the sleeve of larger diameter than the sleeve and having the outerend ofpthe flange extending toward the outside of the -box tfo overhang theend of the sleeve and a stationry hood overhanging the outer end of the 22%.?A In an etching machine'fa paddle assemblage, comprising a plurality of hollow paddle sections, 'a shaft smaller in diameter than the hollow of the. sections,'sleeves one at each end mounted upon the -ishaft, re'- silientgaskets for the paddle wheel sections shaft and to seal and cushion the sections and means upon the shaft for forclng the sleevesand paddle wheel sections together.

AXEL HOLMSTROM.

to support thesections from theA 

